Replaces <img> HTML-Tags with the MkDocs Markdown Syntax

replacer.py

file = open("Skript.md", "r")
newfile = open("new.md", "a")
lines = file.readlines()
replacements = [
    ["<img", "<figure markdown>\n  ![](", "</figure>"],
    ["> <img", "> <figure markdown>\n>   ![](", "> </figure>"],
    ["  <img", "  <figure markdown>\n    ![](", "  </figure>"]
]

for line in lines:
    was_replaced = False
    for r in replacements:
        if (line.startswith(r[0])):
            was_replaced = True
            start_index = 0
            end_index = 0
            for i in range(0, len(line)):
                if line[i] == "=" and line[i+1] == '"':
                    start_index = i+2
                if line[i] == '"' and line[i+1] == ' ':
                    end_index = i
                    break
            image_name = line[start_index:end_index]
            image_name = image_name.replace("Bilder", "assets")
            newfile.write(r[1] +
                          image_name + "){ width=400 }\n" + r[2])

    if (not was_replaced):
        newfile.write(line)